Total Knee Joint Replacement Research Articles

Associations between socioeconomic status and primary total knee joint replacements performed for osteoarthritis across Australia 2003-10: data from the Australian Orthopaedic Association National Joint Replacement Registry.

BackgroundRelatively little is known about the social distribution of total knee joint replacement (TKR) uptake in Australia. We examine associations between socioeconomic status (SES) and TKR performed for diagnosed osteoarthritis 2003–10 for all Australian males and females aged ≥30 yr.MethodsData of primary TKR (n = 213,018, 57.4% female) were ascertained from a comprehensive national joint replacement registry. Residential addresses were matched to Australian Census data to identify area-level social disadvantage, and categorised into deciles. Estimated TKR rates were calculated. Poisson regression was used to model the relative risk (RR) of age-adjusted TKR per 1,000py, stratified by sex and SES.ResultsA negative relationship was observed between TKR rates and SES deciles. Females had a greater rate of TKR than males. Surgery utilisation was greatest for all adults aged 70-79 yr. In that age group differences in estimated TKR per 1,000py between deciles were greater for 2010 than 2003 (females: 2010 RR 4.32 and 2003 RR 3.67; males: 2010 RR 2.04 and 2003 RR 1.78).ConclusionsIdentifying factors associated with TKR utilisation and SES may enhance resource planning and promote surgery utilisation for end-stage osteoarthritis.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2474-15-356) contains supplementary material, which is available to authorized users.

Hospital volume affects outcome after total knee arthroplasty

Background and purpose — The influence of hospital volume on the outcome of total knee joint replacement surgery is controversial. We evaluated nationwide data on the effect of hospital volume on length of stay, re-admission, revision, manipulation under anesthesia (MUA), and discharge disposition for total knee replacement (TKR) in Finland. Patients and methods — 59,696 TKRs for primary osteoarthritis performed between 1998 and 2010 were identified from the Finnish Hospital Discharge Register and the Finnish Arthroplasty Register. Hospitals were classified into 4 groups according to the number of primary and revision knee arthroplasties performed on an annual basis throughout the study period: 1–99 (group 1), 100–249 (group 2), 250–449 (group 3), and ≥ 450 (group 4). The association between hospital procedure volume and length of stay (LOS), length of uninterrupted institutional care (LUIC), re-admissions, revisions, MUA, and discharge disposition were analyzed. Results — The greater the volume of the hospital, the shorter was the average LOS and LUIC. Smaller hospital volume was not unambiguously associated with increased revision, re-admission, or MUA rates. The smaller the annual hospital volume, the more often patients were discharged home. Interpretation — LOS and LUIC ought to be shortened in lower-volume hospitals. There is potential for a reduction in length of stay in extended institutional care facilities.

Epigenetic differences in human cartilage between mild and severe OA

The development of osteoarthritis (OA) depends on genetic and environmental factors, which influence the biology of the chondrocyte via epigenetic regulation. Changes within the epigenome might lead the way to discovery of new pathogenetic pathways. We performed a genome-wide methylation screening to identify potential differences between paired mild and severe osteoarthritic human cartilage. Sixteen female patients suffering from OA underwent total knee joint replacement. Cartilage specimens collected from corresponding macroscopically undamaged and from damaged areas were processed for DNA extraction and histology to evaluate the histological grading of the disease. Paired specimens were analysed for the methylation status of the whole genome using human promoter microarrays (Agilent, Santa Clara, CA). Selected target genes were then validated via methylation-specific qPCR. One thousand two hundred and fourteen genetic targets were identified differentially methylated between mild and severe OA. One thousand and seventy of these targets were found hypermethylated and 144 hypomethylated. The descriptive analysis of these genes by Gene Ontology (GO), KEGG pathway and protein domain analyses points to pathways of development and differentiation. We identified a list of genes which are differently methylated in mild and severe OA cartilage. Within the pathways of growth and development new therapeutic targets might arise by improving our understanding of pathogenetic mechanisms in OA.

The Biomechanical Effect of Loading Speed on Metal-on-UHMWPE Contact Mechanics.

Ultra high molecular weight polyethylene (UHMWPE) is a material commonly used in total hip and knee joint replacements. Numerous studies have assessed the effect of its viscoelastic properties on phenomena such as creep, stress relaxation, and tensile stress. However, these investigations either use the complex 3D geometries of total hip and knee replacements or UHMWPE test objects on their own. No studies have directly measured the effect of vertical load application speed on the contact mechanics of a metal sphere indenting UHMWPE. To this end, a metal ball was used to apply vertical force to a series of UHMWPE flat plate specimens over a wide range of loading speeds, namely, 1, 20, 40, 60, 80, 100, and 120 mm/min. Pressure sensitive Fujifilm was placed at the interface to measure contact area. Experimental results showed that maximum contact force ranged from 3596 to 4520 N and was logarithmically related (R2=0.96) to loading speed. Average contact area ranged from 76.5 to 79.9 mm2 and was linearly related (R2=0.56) to loading speed. Average contact stress ranged from 45.1 to 58.2 MPa and was logarithmically related (R2=0.95) to loading speed. All UHMWPE specimens displayed a circular area of permanent surface damage, which did not disappear with time. This study has practical implications for understanding the contact mechanics of hip and knee replacements for a variety of activities of daily living.

The negative influence of multiple symptomatic joint involvement on patient-reported outcomes following TJR for OA can last up to 5 years

Purpose: Patient-reported pain and physical function are the most common outcomes examined in total joint replacement (TJR) for hip and knee osteoarthritis (OA). While TJR is an effective treatment for relieving pain and improving function, previous work has shown that the reporting of multiple symptomatic joints at the time of surgery negatively impacts 1-yr outcome scores. However, whether these negative effects persist beyond the recovery period is unknown. This work evaluated whether the presence of symptomatic joints predicted worse pain and physical function scores over a five year period following TJR. Methods: Participants completed a health questionnaire including the hip/knee-specific WOMAC pain and physical function measures pre-surgery and at 3, 6, 12 and 60 months post-surgery. Higher scores reflected worse status. Symptomatic joints were indicated on a homunculus pre-surgery based on pain or discomfort on most days of the previous month. Not including the surgical joint, symptomatic joint count was categorized as 0-1, 2-4, and 5+ (each group representing about one-third of the sample). Individuals reporting other hip or knee TJR during the 5 years of follow-up were not included in this analysis. Linear GEE regression modeling (accounting for the within-person correlated scores over time) was used to examine the relationship between symptomatic joint count and hip/knee-specific pain and physical function scores over the five years. Model covariates included age, sex, body mass index, comorbidity, hip/knee, and time since surgery. Results: 433 participants provided data up to and including the 5th year post-surgery. Age at surgery ranged from 35-88 years (mean = 65) with 61% female. At baseline 36% reported 0-1 symptomatic joints, 34% reported 2-4, and 30% reported 5+ symptomatic joints. No baseline differences in age, sex, surgical joint, BMI, or symptomatic joint counts were found between those who did and did not complete the 5th year survey. While there were statistical differences for baseline pain and physical function, the magnitude of these differences were small: 0.7 and 3 units on scales ranging from 0-20 and 0-68, respectively. Significant time trends for improvement in pain and physical function scores were found. Adjusting for covariates, increasing joint count was associated with worse pain and function scores throughout the 5 year follow-up (all p-values < 0.006), and more so for physical function. Accounting for baseline covariate effects, the least square mean differences at 5 years between those in the highest and lowest symptomatic joint count categories were nearly 2 for pain and 7.4 for physical function. Conclusions: While TJR is an effective intervention, these study results suggest that joint-specific patient-reported outcomes are negatively influenced by more than the symptoms of the surgical joint alone. Further, it appears that these negative effects are not limited to the early recovery period, and rather persist for many years following surgery. This knowledge should inform rehabilitation strategies post-TJR and the need for ongoing follow-up. The findings also potentially speak to a need for a more holistic approach to OA management.

Guideline recommendations for post acute postoperative physiotherapy in total hip and knee joint replacement surgery: are they used in daily clinical practice?

Guideline recommendations for post acute postoperative physiotherapy in total hip and knee joint replacement surgery: are they used in daily clinical practice?

A5.9 Sphingosine-1-phosphate counteracts interleukin-1β in human chondrocytes.

Background and ObjectivesThe lipid mediator Sphingosine-1-phosphate (S1P) is found in the synovial fluid of osteoarthritis (OA) patients. S1P protects bovine cartilage by counteracting interleukin-1β (IL-1β). Here we examine the interaction...

A5.17 Comparison of adipose mesenchymal stem cells derived from rheumatoid arthritis and osteoarthritis patients. The influence of adipocytokines

Background and ObjectivesAdipose-derived stem cells (ASCs) have immunomodulatory properties and are intensively studied as a potential therapeutical method to treat rheumatoid arthritis (RA). ASCs immunosuppressive function may be affected by...

Community Reintegration Following a Total Joint Replacement: A Pilot Study

To examine community reintegration following a hip or knee total joint replacement (TJR) from the perspective of rehabilitation clients. A phenomenological frame of reference guided the present study. Ten participants who received inpatient rehabilitation completed semi-structured qualitative interviews to explore their experiences with reintegrating back into their chosen communities and the meanings that they ascribed to their reintegration. Interview data were analysed using thematic analysis. Demographic data, and information regarding participants' living situation and supports were extracted from existing databases and used to characterize the sample. Participants revealed that reintegration after a TJR encompassed two key elements of meaning: i) engagement in meaningful activities; and ii) satisfaction levels. Additionally, the following five factors were identified as facilitators or barriers to community reintegration following a TJR: i) ongoing preparation and education; ii) confounding health issues; iii) driving and transportation; iv) personal facilitators; v) access to supports from professionals, family and friends, and community programmes. The present study highlights the significance of engaging in meaningful activities and being satisfied in one's level of engagement to achieving a sense of community reintegration following a TJR. This suggests that reintegration post-TJR has broader meanings than just improvements in functional abilities. Practitioners are encouraged to inquire about patients' meaningful activities, support their preparedness throughout the rehabilitation process, to identify confounding health issues that may limit reintegration, consider patients' fears and anxieties and establish supports to enhance their feelings of self-efficacy and abilities to cope following a TJR.

Arthroscopic characteristics of meniscal injuries in osteoarthritic knees.

The aim of this study was to investigate the arthroscopic characteristics of meniscal injuries in osteoarthritic knees and explore their significance in the selection of surgical approach. Four original types of meniscal injuries were defined. The study included 87 cases; 12 Type 1, 26 Type 2, 35 Type 3 and 14 in Type 4 meniscal injuries. For Type 1 injuries, 5 cases underwent meniscal suture repair and 7 cases partial meniscal resection. Partial meniscal resection was performed in 22 cases and subtotal resection in 4 cases of Type 2 injury. For Type 3 injury, meniscal debridement was performed in 2, partial resection in 8, subtotal resection in 19 and total resection in 6 cases. For Type 4 injury, 3 cases underwent subtotal resection and 11 underwent total resection. Patients were evaluated with the Lysholm, visual analog scale, and Kellgren-Lawrence scale scores and cartilage lesions stages. Mean follow-up period was 26 (range: 8 to 51) months. Joint swelling or pain was present in 13 cases after fatigue. Twist lock symptom was observed in one Type 3 injury and one Type 4 injury. Joint flexion was limited to 20° in one Type 3 injury and two Type 4 injuries. Total knee joint replacement was performed in two Type 2 and two Type 4 injuries 2 to 3 years and 2 months after surgery. The classification of meniscal injuries in osteoarthritic knees was designed to guide arthroscopic surgery and improve the therapeutic efficacy of minimally invasive surgery for knee osteoarthritis.

The Effect of Tranexamic Acid on Blood Loss during Total Knee Arthroplasty

Background: Tranexamic acid is antifibrinolytic drug which has the property to reduce intraoperative and postoperative bleeding. There are several studies supporting the use of tranexamic acid in total knee joint replacements and few in total hip replacements. This study was intended to establish the effects of tranexamic acid in minimizing the intra operative and post operative blood loss in total knee arthroplasty. Material and methods: This was a prospective follow up study conducted in Father Muller Medical College , Mangalore over period of 4 months from August 2013 to November 2013. A total number of 30 patients who underwent total knee arthroplasty were included for this study. The patients were grouped as treatment and control group. The treatment group and control group were selected by purposive sampling. In the treatment group, the patients undergoing total knee arthroplasty received single dose of intravenous tranexamic acid 10mg/kg body weight 5 minutes before skin incision and equal volume of saline was injected in the control group. Intra operative blood loss was calculated by galvanometric method 20 , weighing the sponges used and soiled by blood during surgery and measuring the amount of blood collected in suction apparatus used during the surgery. The haemoglobin level assessed post operatively and compared with preoperative haemoglobin level. The amount of fluid collected in the post-operative drain were also measured. All the collected data are analyzed with Fisher exact test. Conclusion:Tranexamic acid administrated before surgical incision is efficient in reducing bleeding during common surgeries around the hip joint. Especially surgery where more amount of blood loss was expected, like total joint replacement and hemiarthroplasty, the drug had shown significant benefit compared with the control group.

Sphingosine 1‐Phosphate Counteracts the Effects of Interleukin‐1β in Human Chondrocytes

ObjectiveThe lipid mediator sphingosine 1-phosphate (S1P) is found in the synovial fluid of osteoarthritis (OA) patients. S1P protects bovine cartilage by counteracting the effects of interleukin-1β (IL-1β). This study was undertaken to examine the interaction of S1P and IL-1β in human OA chondrocytes.MethodsHuman cartilage was obtained from patients undergoing total knee joint replacement. Chondrocytes were cultured in monolayer and treated with IL-1β and S1P. Expression of S1P receptor subtypes and genes involved in cartilage degradation was evaluated using real-time polymerase chain reaction, immunohistochemistry, and Western blotting. S1P signaling was evaluated using inhibitors of S1P receptors and small interfering RNA (siRNA) knockdown of the S1P2 receptor. Phosphorylation of MAP kinases and NF-κB in response to IL-1β and S1P was detected by Western blotting.ResultsS1P2 was identified as the most prevalent S1P receptor subtype in human OA cartilage and chondrocytes in vitro. S1P reduced expression of inducible nitric oxide synthase (iNOS) in IL-1β–treated chondrocytes. Reduction of ADAMTS-4 and matrix metalloproteinase 13 expression by S1P correlated with S1P2 expression. Pharmacologic inhibition of the S1P2 receptor, but not the S1P1 and S1P3 receptors, abrogated the inhibition of iNOS expression. Similar results were observed using siRNA knockdown. S1P signaling inhibited IL-1β–induced phosphorylation of p38 MAPK.ConclusionIn human chondrocytes, S1P reduces the induction of catabolic genes in the presence of IL-1β. Activation of the S1P2 receptor counteracts the detrimental phosphorylation of p38 MAPK by IL-1β.

Properties of open-cell porous metals and alloys for orthopaedic applications

One shortcoming of metals and alloys used to fabricate various components of orthopaedic systems, such as the femoral stem of a total hip joint replacement and the tibial plate of a total knee joint replacement, is well-recognized. This is that the material modulus of elasticity (E') is substantially larger than that of the contiguous cancellous bone, a consequence of which is stress shielding which, in turn, has been postulated to be implicated in a cascade of events that culminates in the principal life-limiting phenomenon of these systems, namely, aseptic loosening. Thus, over the years, a host of research programs have focused on the synthesis of metallic biomaterials whose E' can be tailored to match that of cancellous bone. The present work is a review of the extant large volume of literature on these materials, which are called open-cell porous metals/alloys (or, sometimes, metal foams or cellular materials). As such, its range is wide, covering myriad aspects such as production methods, characterization studies, in vitro evaluations, and in vivo performance. The review also includes discussion of seven areas for future research, such as parametric studies of the influence of an assortment of process variables (such as the space holder material and the laser power in the space holder method and the laser-engineered net-shaping process, respectively) on various properties (notably, permeability, fatigue strength, and corrosion resistance) of a given porous metal/alloy, innovative methods of determining fatigue strength, and modeling of corrosion behavior.

AB0992 Knee lavage versus intra articular hyaluronan in advanced knee osteoarthritis

BackgroundMany patients with advanced knee osteoarthritis (OA) who are indicted for total knee joint replacement (TKR) are unfit for operation or refuse it for different reasons. Palliative treatment for this...

SAT0311 A Randomized Double-Blind Control Trial of Intra-Articular Hyaluronic Acid:Botulinum Toxin Type a Versus Placebo for Mild to Moderate Knee OA

BackgroundMild to moderate osteoarthritis (OA) knee pain is often poorly controlled despite recommendations of efficacious therapy. These are compounding in the fact that many patients are either intolerant to some...

Endovascular repair of popliteal artery pseudoaneurysm with covered stent following total knee joint replacement

Endovascular repair of popliteal artery pseudoaneurysm with covered stent following total knee joint replacement

AB0143 Osteogenic potential of mesenchymal stem cells from articular adipose tissue – comparison of rheumatoid arthritis and osteoarthritis

BackgroundAdipose-derived mesenchymal stem cells (ADSC) have the ability to differentiate into osteoblasts. This makes them promising in treatment of bone erosion occuring in rheumatoid arthritis (RA). ADSC residing in rheumatoid...

AB0110 Adipocytokines modify the expression of indoleamine 2,3-dioxygenase and HEM oxygenase-1 in rheumatoid mesenchymal stem cells from articular adipose tissue

BackgroundWhite adipose tissue (WAT) is a rich source of mesenchymal stem cells (ADSC) which immunomodulatory and regenerative properties are well documented. Therapeutic effect of ADSC in experimental animal model of...

Combining μX-ray fluorescence, μXANES and μXRD to shed light on Zn2+ cations in cartilage and meniscus calcifications

We aimed to examine the presence of Zn, a trace element, in osteoarthritis (OA) cartilage and meniscus from patients undergoing total knee joint replacement for primary OA. We mapped Ca2+ and Zn2+ at the mesoscopic scale by X-ray fluorescence microanalysis (μX-ray) to determine the spatial distribution of the 2 elements in cartilage, μX-ray absorption near edge structure spectroscopy to identify the Zn species, and μX-ray diffraction to determine the chemical nature of the calcification. Fourier transform infrared spectroscopy was used to determine the chemical composition of cartilage and meniscus. Ca2+ showed a heterogeneous spatial distribution corresponding to the calcifications within cartilage (or meniscus) or at their surface. At least 2 Zn2+ species were present: the first may correspond to Zn embedded in protein (different Zn metalloproteins are known to prevent calcification in biological tissues), and the second may be associated with a Zn trap in or at the surface of the calcification. Calcification present in OA cartilage may significantly modify the spatial distribution of Zn; part of the Zn may be trapped in the calcification and may alter the associated biological function of Zn metalloproteins.

Clinical immunology Comparison of phenotype, chondrogenic and osteogenic potential of rheumatoid mesenchymal stem cells derived from articular and subcutaneous adipose tissue - the role of adipocytokines

A study was carried out to compare the phenotype, chondrogenic and osteogenic potential of adipose mesenchymal stem cells (ASCs) derived from articular adipose tissue (AAT) and subcutaneous adipose tissue (ScAT) of rheumatoid arthritis (RA) patients. We also aimed to evaluate the role of leptin (LEP), low molecular weight adiponectin isoform (LMW), high molecular weight adiponectin isoform (HMW) and tumor necrosis factor (TNF) in ASCs differentiation. AAT and ScAT were obtained from RA patients undergoing total knee joint replacement surgery. ASCs were isolated and expanded in vitro. Cells phenotype was assesed by flow cytometry; leptin and adiponectin receptors mRNA expression by RT-PCR. Differentiation was performed in chondrogenic and osteogenic medium with or without LEP, LMW, HMW and TNF. After differentiation, expression of mRNA for Sox9, aggrecan (Agr), collagen 2a (Col2a) for chondrogenesis, and BMP-2, Runx-2 and osteopontin (OPN) for osteogenesis was evaluated by RT-PCR. Dickkopf-1 (DKK-1) and osteoprotegerin (OPG) proteins concentrations were measured in supernatants from osteogenic cultures using ELISA. AAT and ScAT-ASCs have the same CD105+CD90+CD73+CD45–CD34+/–CD19–CD14– phenotype. AAT-ASCs seem to be more susceptible to chondrogenesis and osteogenesis in vitro. Adipocytokines do not exert strong effect on ASCs differentiation, however HMW slightly increased expression of chondrogenesis markers mRNA in AATASCs. TNF diminished expression of all chondrogenesis markers and OPN, but enhanced expression of BMP-2 and Runx-2 mRNA.